Functional strength exercise machines are known for allowing a user to perform complex movements relatively free in space, imitating traditional free weight exercises (dumbbells, barbells, etc.) with the possibility to perform an extended range of exercises. Those machines are generally composed by a resisting load carried to a grip element through a cable, typically sliding around a certain number of pulleys. The resistant load may be “generated” through weights stacks, resistance devices, pneumatic or electric actuators.
In this kind of machines, the resisting load (namely the force that the user perceives at the grip element and to which he must counteract to make a specific movement) always acts along the direction of the cable that carries the load to the grip element. Similarly, if the grip element involves more cables or more segments of the same cable (as an example, possible configurations are shown in FIG. 1), the resisting force direction perceived by the user is given by the vector sum, as shown in FIG. 1.
In U.S. Pat. No. 7,670,270 an exercising machine is disclosed, which is provided with a frame and with at least one operating apparatus. The at least one operating apparatus can be used to perform a physical exercise and comprises a load group supported by the frame and connected to the operating apparatus by means of at least one cable wound around a plurality of transmission members supported by the frame and arranged so as to define a path for the cable. The load group comprises at least two load units separated from each other and connected together by means of the cable and arranged at ends of the path on opposite sides of the operating apparatus so that the latter can be tensioned on respective opposite sides by means of different loads.
In U.S. Pat. No. 4,402,504 another example of exercising machine is disclosed, which comprises an elongated frame including an upper pulley and a lower pulley attached to the upper and lower portions of the frame, respectively. A resistance means operatively connected to the frame provides an exercising force in response to exercising motions of the user. A two-ended cable is trained around the upper and lower pulleys with its ends connected to the resistance means. A grip, slidably attached to an intermediate portion of the cable, is trained around and between two guide pulleys attached to a carriage that is carried by the frame. Guide pulleys guide the intermediate portion of the cable laterally outwardly form the carriage to provide a working loop for engagement by the grip. The height of the carriage is selectively adjustable relative to the frame. The length of the working loop remains substantially constant when not pulled, regardless of the height of the carriage. The resistance means may comprise resilient resistance straps, coiled springs or weights.
In US-A-2014/0121071 an exercise machine is disclosed which comprises a frame and a weight stack. The weight stack is positioned within a portion of the frame. The exercise machine further comprises a weighted cable having a first end configured for selective attachment to weight plates of the weight stack, a guide track defining a path, and a movable pulley assembly slidably coupled to the guide track. A positioning mechanism is coupled to the movable pulley assembly and configured to move and position the movable pulley assembly along the path defined by the guide track.